Srping框架搭建

Dear 丶 2022-05-07 06:00 193阅读 0赞

1.导包（导入依赖）

![70][]

spring 依赖的结构图

spring

导入核心包

<properties>
        <spring.version>5.0.2.RELEASE</spring.version>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>
    <dependencies>
        
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>
        
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>
        
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>${spring.version}</version>
        </dependency>
    </dependencies>

2.书写配置文件

applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
           xmlns:aop="http://www.springframework.org/schema/aop"
           xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans.xsd
           http://www.springframework.org/schema/context
           http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
    </beans>

3.准备一个类

public class User {
        private String username;
        private Integer uid;
        private Integer age;
        private Double balance;
    
        @Override
        public String toString() {
            return "User{" +
                    "username='" + username + '\'' +
                    ", uid=" + uid +
                    ", age=" + age +
                    ", balance=" + balance +
                    '}';
        }
    
        public String getUsername() {
            return username;
        }
    
        public void setUsername(String username) {
            this.username = username;
        }

public Integer getUid() {
            return uid;
        }
    
        public void setUid(Integer uid) {
            this.uid = uid;
        }
    
        public Integer getAge() {
            return age;
        }
    
        public void setAge(Integer age) {
            this.age = age;
        }
    
        public Double getBalance() {
            return balance;
        }
    
        public void setBalance(Double balance) {
            this.balance = balance;
        }
    }

4. 把创建好的类交给spring管理（在spring的配置文件中配置这个类）

5.书写测试代码

让spring帮我们new 出来一个对象

ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
    User user = (User) applicationContext.getBean("user");
    System.out.println(user);

ClassPathXmlApplicationContext是spring框架的工厂类

![70 1][]

BeanFactory 这个类是spring框架在最开始用的类，

现在用的是 FileSystemApplicatonContext (使用配置的绝对路径读取) ClassPathXmlApplicationContext（使用配置文件的相对路径）

BeanFactory适用于资源匮乏的时代，当使用对象的时候spring容器才帮助你创建一个对象

File… 和Class… 适用于资源富余的时代，当读取配置文件的时候，一次性将spring容器中的所有对象全部创建，随时取随时用。他的效率要比ApplicationContext高

ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");//该行代码执行完毕后，spring容器中的所有对象都被创建
    如果使用的是ApplicationContext 则不会创建直到使用该对象时才会创建

Spring配置文件详解

<bean  name="user" class="com.hd.bean.User" scope="singleton" init-method="before" destroy-method="after"></bean>
    
    
    
    
    <bean name="staticUserFactory" class="com.hd.B_create.StaticFactory" factory-method="createUser"></bean>
    
    <bean name="userFactory" class="com.hd.B_create.UserFactory" ></bean>
    <bean name="user2" factory-bean="userFactory" factory-method="createUser"></bean>

属性注入

set方法的注入

<bean name="computer" class="com.hd.C_di.Computer">
            <property name="color" value="黑色"></property>
            <property name="type" value="Think Pad"></property>
        </bean>
        <bean name="student" class="com.hd.C_di.Student">
            <property name="name" value="李欢"></property>
            <property name="age" value="19"></property>
            <property name="computer" ref="computer"></property>
        </bean>

构造函数的注入

<bean name="student1" class="com.hd.C_di.Student" >
        <constructor-arg name="name2" value="仉宏志"  index="0" type="java.lang.String"></constructor-arg>
        <constructor-arg name="age1" value=""></constructor-arg>
        <constructor-arg name="addr" value="asdf"></constructor-arg>
    </bean>

p(propertity的缩写)空间的注入

spel的注入 适用于已知的对象输入注入

<bean name="spel_student" class="com.hd.C_di.Student">
        <property name="name" value="#{student.name}"></property>
    </bean>

复杂类型的注入

数组

list

set

<property name="set">    <set>        <ref bean="p_student"></ref>        <value>hello</value>    </set></property>

map

properties

数组  list  set properties 如果只有值，就可以按照原有的方式注入

[70]: /images/20220506/4cbb8525bc0a4b9fa7564cc581838f3a.png
[70 1]: /images/20220506/18f59b0c686540ca806be5595e16a183.png